<p><em>Optional. Default <code>false</code>.</em> Set to <code>true</code> to auto-trigger
new builds of the plan's job whenever this step has new versions available,
as specified by the <code>resource</code> and any <code>passed</code> constraints.</p><p>Otherwise, if no <code>get</code> steps set this to <code>true</code>, the job can only
be manually triggered.</p>